1. Field of the Invention
The invention relates to a radial compressor stage for a radial compressor.
2. Description of the Related Art
From DE 195 02 808 C2 and from DE 10 2012 203 801 A1 the fundamental structure of a radial compressor with at least one radial compressor stage is known. Accordingly, it is disclosed in this state of the art that the, or each, radial compressor stage of a radial compressor comprises an impeller that rotates with respect to a stator, wherein the impeller comprises multiple impeller blades on the rotor side. Each impeller blade of an impeller accordingly comprises a flow inlet edge and a flow outlet edge, wherein between the flow inlet edge and the flow outlet edge of each impeller blade a suction side, a pressure side and an outer surface facing the stator extend, wherein the outer surface of the respective impeller blade borders on the stator and serves for the sealing with respect to the stator. Such an impeller of a radial compressor, in which the outer surfaces of the impeller blades indirectly border on the stator, does not have a cover band and is also called an open impeller.
Under unfavorable operating conditions, the outer surfaces of the impeller blades of an impeller can run into the stator or rub against the stator, as a result of which damage in the region of the outer surfaces of the impeller blades and of the stator can occur. In particular when, for reducing the risk of damage on the outer surfaces of the impeller blades of an impeller facing the stator, material is removed for reducing the material thickness of the impeller, the sealing effect in the region of the outer surfaces of the impeller blades relative to the stator deteriorates.
There is a need for a radial compressor stage in which the risk of damage in the region of the outer surfaces of the impeller blades is reduced, in which however a good sealing effect of the outer surfaces with respect to the stator is ensured.